Retaining-valve.



No. 7||.774. Patented oct. 2|, |902.

w. G. LAMB.

RETAINING VALVE.

(Applicatiun led July 9, 1902.) (Nq Model.)

UNITED STATES.4

PATENT OFFICE.

WILLIAM GOTT LAMB, OF MEXICO, MEXICO.

RETAlNlNG-VALVE.

SPECIFICATION vforming` part of Letters PatentNo. 711,774, dated October 21, 192. Application filed July 9, 19702- Serial No. 114,903. (No model.)

To @ZZ whom, it may concern:

Be it known that I, WILLIAM GOTT LAMB, a citizen of the United States, and a resident of the city of Mexico, Mexico, have invented a new and Improved .Retaining-Valve,v of which the following is a full, clear, and exact description.

The invention relates to` fluid pressure brakes of the Westinghouse type, and more particularly to retaining valves such as shown and described in the Letters Patent of the United States No. 702,802, granted to me June 17, 1902.

The object of the invention is to provide a new and improved retaining-valve arranged to automatically hold the full' pressure on the brakes while recharging the auxiliary reservoir and to insure a proper release of the brakes whenever the train-pipe is recharged, the retaining-valve being exceedingly sensitive in operation.

The invention consists of novel features and parts and lcombinations of the same, as Will be more fully described hereinafter and then pointed out in the claims.

A practical embodiment of the invention is represented in the accompanying drawings,V forming a part of this specification, in which,

similar characters of reference indicate corresponding,r parts in all the Views. 1

Figure lis a sectional side elevation of the improvement as applied. Fig. 2 is a plan viewA of the same. Fig. 3 is an enlarged transverse i section of the improvement on the line 3 8 of Fig. 1, and Fig. 4: isasectionalrplanview of the same on the line 4 4: of Fig. 3. y

The improved retaining-valve A, as illustrated in the drawings, is connected with the exhaust of the triple valve B and the auxiliary reservoir C, and for the purpose mentioned a pipe D leads from the exhaust of the triple valve B to the lowerend of the retaining-valve A,and a pipe E connects the auxiliary reservoir C with the middle portion of the retaining-valve A, as hereinafter more fully described.

The retaining-.valve A is provided with a casing or valve-body preferably'made in several parts, and the lower part F of these sections is connected with the pipe D and contains a valve-seat F', adapted to be closed by a valve G under pressure from the exhaust of the triple valve. The valve G is provided with an upwardly-extending stem G', carrying a piston G2, mounted to slide in the cylinder F2, formed on the part F, the said stem G' passing through a partition F3, dividing the cylinder F2 from an exhaust-chamber F4, having an outlet-port a to the atmosphere to allow the air to escape from the triple-valve exhaust, as hereinafter more fully described;

The valve G is provided in its bottom with a valve-seat H', opening into a valve-chamber G3, formedy in the top of the valve G, the said chamber having ports a' opening into theexhaust-chamber F4 to connect the interior of the chambers G2 and Fl With each other. A valve H is seated on thevalve-seat H' and opens upward into the' chamber Gsagainst the tension of a spring'H2, set to, say, twenty pounds, andserves to hold the valve H normally to its seat H'.

At the top of the cylinder F2 is screwed or otherwise secured the middle part I of the retainer-valve casing, and on the said part I screws the pipe E, previously mentioned, the said pipe E connecting by a port b with a chamber I', formed in its bottom with a needle-point-valve seat I2 for connecting the chamber I' With the top of lthe cylinder F2. AThe seat 12 is engaged by the needle-point J' -of a diaphragm-valve J, having its diaphragm seated on a gasket K, held on the under side of the top part L of the casing or valve-body, the said .top part being screwed or otherwise secured to the top of the middle part I. The body J2 of the diaphragm-valve J is pressed on by a spring N, contained inthe top part L and resting against the under side of a plug O, adjustable in the part L to regulate the tension of the spring N and allow of setting the valve .I at the desired pressure. The spring N is set, say, to seventy pounds.

The upper end of the cylinder F2 is connected by a port c with aV small auxiliary cylinder P, containing a piston Q, having an annular groove Q'- for connecting the ports c with a port d, formed inthe wall of the cylinder P and leading to the atmosphere. A spring R, set, say, to fifty pounds, presses against the under side of the piston Q to normally hold the piston in such a position that its groove Q registers with both ports c and d to relieve the upper end of the cylinder F2 ICO duced to, say, iifty pounds, as the piston ofthe cylinder F2 to force the piston G2 down-v ward, so that the valve G moves from its seat F' to allow thevexhaust from the triple valve B to pass through the valve-seat F into the chamber F4 and by the port a to the atmosphere to release the brakes. The pressure of seventy pounds from the auxiliary reservoir passes by way of the portf into the upper end of the cylinder P to force the piston Q therein downward against the tension of the spring R, set to only fifty pounds, as previously mentioned. A downward movement of the piston Q disconnects the annular groove Q' from the ports b and c to close the same, and hence the air which entered the upper end of the cylinder F2 from the chamber I', as previously described, cannot escape from the cylinder F2 during the release of the brakes.

In applying the brakes, the pressure in the auxiliary reservoir and Atrain-pipe being rethe brake-cylinder is forced ahead the spring N forces the valve J downward against the reduced pressure in the chamber I and causes the needle-point J to move to its seat 12, and thereby disconnect the chamber I from the upper end of lthe cylinder F2. When the valve J is in such position and brakes released, then the exhaust from the triple valve, acting on the piston G2, causes the piston to slide upward in the cylinder F2 to move the valve G to its seat, and the exhaust now opens the valve H against the tension of the spring H2, so that the exhaust now passes through the valve-chamber G3 and port a' into the chamber F4 and by way of the port o. to the atmosphere. The valve H remains open until the pressure is reduced to twenty pounds. Then the spring H2 closes the valve H, so as to retain, say, twenty pounds of pressure in the brake-cylinder. This pressure inthe brake-cylinder keeps the brake supplied until the auxiliary reser- Voir is replenished to the full pressure-that is, to seventy pounds-after which the abovedescribed operation is repeated-that is, the pressure of seventy pounds in the chamber I causes the diaphragm-valve J to move the needle-point J from its seat 12to allow this pressure to act on the piston G2 and force the valve G off its seat to allow escape of air from the exhaust of the triple valve, as above mentioned. When the reduction in the auxiliary reservoir takes place-f-say to fifty pounds or belowthen the spring R forcesthe piston Q upward to bring the groove Q' in register with the ports c and d to allow the air inthe upper end of the cylinder F2 to escape to the atmosphere by way of the port c, groove Q', and port d. By this arrangement the piston G2 readily moves up under exhaust-pressure from the brakecylinderthatl is, the piston G2 -and'its valve G are rendered very sensitive.

From the foregoing it will be seen that the engineer is enabled to recharge the auxiliary reservoir to the full pressure without releasing the brakes, and this arrangement is therefore serviceable on long steep grades, as then the pressure is considerably reduced by leakage and it often becomes necessary to recharge the auxiliary reservoir to keep the brakes supplied. N ow it is evident that if the brakes have to be released from time to time on a long steep downgrade while recharging the auxiliary reservoir, as heretofore practiced, it frequently happens that the train obtains such a momentum as to become completely out of control of the engineer. By my improvement above described the brakes remain supplied, say, with twenty pounds pressure (more or less according to the tension to which the spring H2 is set) without recharging the auxiliary reservoir, the twenty pounds being suicient to brake the wheels Without sliding the same on the rails.

The pipe D, previously mentioned, is provided with a cock D' for connecting the pipe D directly with the atmosphere, so that in case the retaining-valve is out of order then the triple-valve exhaust passes directly to the atmosphere the same as if the retainingvalve were not employed.

Having thus described my invention, YI claim as new and desire to secure by Letters Patentl. A retaining-valve comprising a valvecasing connected with the exhaust of the triple valve and with the auxiliary reservoir, a releasepiston valve in the Valve-casing, normally held to its seat by the exhaust from the triple valve, a spring-pressed auxiliary valve on the said release-piston, adapted to be opened by the exhaust from the triple valve to connect the exhaust with the atmosphere, and a spring-pressed diaphragm needle-point valve in the said casing, set to a desired pressure and controlled by pressure from the auxiliary reservoir, the said needlepoint valve controlling a valve-seat, to permit pressure from the auxiliary reservoir to act on the piston of the said release-piston valve, to move the latter into an open position for the escape of the exhaust from the triple valve to the atmosphere, as set forth.

2. A retaining-valve comprising a valvecasing connected with the exhaust of the triple valve and with the auxiliary reservoir, a release-piston valve in the valve-casing, normally held to its seat by the exhaust from the triple valve, a spring-pressed auxiliary IOO IIO

valve on the said release-piston, adapted to be opened by the exhaust from the triple valve to connect the exhaust with the atmosphere, a spring-pressed diaphragm needlepoint valve in the said casing, set to a desired pressure and controlled by pressure from the auxiliary reservoir, the said needle point valve controlling a valve-seat, to permit pressure from the auxiliary reservoir to act on the piston of the said release-piston valve, to move the latter into an open position for the escape of the exhaust from the triple valve to the atmosphere, and a springpressed discharge-valve, for allowing the air-pressureto escape to the atmosphere from the cylinder of the piston of the release-piston valve, the said discharge-valve being controlled by pressure from the auxiliary reservoir, as set forth.

3. A retaining-valve comprising a valvecasing connected With the exhaust of the triple valve and with the auxiliary reservoir,

voir, as set forth.

In testimony whereof I have signed my name to this specification in the presence of tWo subscribing Witnesses.

WILLIAM GOTT LAMB.

Witnesses:

A. S. LAMB, L. P. FRISBIE. 

